Ncert – class 8- science – Chapter 10: Sound 2 Welcome to your Ncert - class 8- science - Chapter 10: Sound 2 1. A musical instrument is producing a continuous note. This note can not be heard by a person having a normal hearing range. This note must then be passing through: vacuum water wax empty vessel None 2. Which of the following vibrates when a musical note is produced by the cymbals in an orchestra? Stretched strings Air columns Metal plates Stretched membranes None 3. A sound wave has a speed of 200 m/s in a medium and it travels a distance of 1 m. What is the time taken by the wave to cross the medium 10 ms 5 ms 100 ms 50 ms None 4. The maximum displacement of a particle in a vibratory motion is known as Amplitude frequency Time period Wavelength None 5. The safe limit of loudness of audible sound is above 120 db 120 db above 80 db 0 to 80 db None 6. A particle takes 0.01 s to complete 5 vibrations, what is its frequency 500Hz 5 Hz 50Hz 10Hz None 7. A particle completes one vibration in 2 secs. How long does it take to vibrate 25 vibrations 50 sec 25 sec 10 sec 5 sec None 8. The loudness of sound is determined by the Frequency of vibration The ratio of amplitude and frequency of vibration Product of amplitude and frequency of vibration Amplitude of vibration None 9. Name the instruments for which more than one part is responsible for the production of sound. Tabla Guitar Violin All of the above None 10. Which of the following vibrating parts of instrument is not matched with the respective instrument Tabla - Stretched Membrane Mridangam - Stretched Membrane None of the above Drum- Stretched Membrane None 11. A sound wave, whose time period is 3 s passes through a medium for 30 s. The number of waves that had passed through is: 10 waves 5 waves 3 waves 1 wave None 12. Sound waves having the following frequency are audible to human beings: 27000 cycles/sec 50,000 cycles/sec 5 cycles/sec 5000 cycles/sec None 13. Match the following columns and select the correct option from the codes given below.Column IColumn II(i) Pressure(p) Pattern formed due to multiple reflections(ii) Decibel(q) Unit of loudness(iii) Richter(r) Force per unit area(iv) Kaleidoscope(s) Scale to measure the intensity of (i) - (r), (ii) - (q), (iii) - (s), (iv) - (p) (i) - (p), (ii) - (r), (iii) - (s), (iv) - (q) (i) - (p), (ii) - (s), (iii) - (r), (iv) - (q) (i) - (q), (ii) - (p), (iii) - (s), (iv) - (r) None 14. A chain of hydrogen bombs is being exploded every time in the sun due to the fusion process, yet you do not hear the sound, because. The sound so generated dissipates away The sound so generated is absorbed by various layers of the sun The space between the sun and the earth is void The sun is very far away None 15. An astronaut can not hear his companion's sound at the surface of moon because: none of the above temperature is too low during night and high during day sound wave does not propagate through vaccum produced frequencies are above the audio frequency None Time's up Please Share This Share this content Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Leave a Reply Cancel replyCommentEnter your name or username to commentEnter your email address to commentEnter your website URL (optional) Save my name, email, and website in this browser for the next time I comment.
